Mirror Networking

This is a guide on how to configure two Unity clients that connect to each other using the open source Mirror Networking package. It has nothing to do with Catena itself, but is supplemental material to get you up and running with a baseline Unity project that can make use of Catena's features.

Note: This guide uses code and information from Shrine's Mirror Networking series on YouTube.

Estimated Time

Setting up this demo is estimated to take <10 minutes.

Prerequisites

• Unity Editor, version 2021.3.35 or higher

Initial Setup

Install The Dedicated Server Module

1. Open your Unity Project
2. Open "Build Profiles" by navigating to File -> Build Profiles
3. Select "Windows Server"
4. Select "Install with Unity Hub" if "No Windows Server module loaded" is displayed. If not, you are done with this step.
5. If you needed to install, select "Windows Dedicated Server Build Support" in the Unity Hub Window that popped up.
6. Install.
7. Once installed, restart your editor.

Download + Install The Mirror Sample

1. Open your Unity Project
2. Open the Asset Store by navigating to Window -> Asset Store
3. Search for "Mirror"
4. Select the "Mirror" Asset from "Mirror Networking". You can also find a link directly to Mirror here
5. Select "Open in Unity"
6. In Unity, select "Download"
7. Select "Import"
   1. If prompted to "Install/Upgrade" dependencies, do so
8. Import all

Download + Install ParrelSync

ParrelSync is a Unity editor extension that allows developers to test multiplayer gameplay without building project binaries. This is accomplished by having another Unity Editor window opened which ParrelSync mirrors the changes to from the original project.

1. Open the Package Manager by navigating to Window -> Package Manager
2. Select the + to add a package
   1. Select "Add package from git URL..."
   2. Paste the following URL: https://github.com/VeriorPies/ParrelSync.git?path=/ParrelSync
3. You will now see a "ParrelSync" option in the toolbar at the top of the Unity Editor
4. Open the Clones Manager by navigating to ParrelSync -> Clones Manager
5. Select "Create new clone"
6. When your clone is created, select "Open in New Editor"
7. Changes that are made in your original editor will now automatically be mirrored into the clone editor, which we will use later to test our multiplayer functionality

Create Your Multiplayer Experience

Setting Up The Network Components

1. Select the scene you would like to add Multiplayer functionality to. If you are starting from a fresh Unity project, this will be located at Assets/Scenes/SampleScene.unity
2. Create an empty GameObject in your Scene and name it NetworkManager
3. Add three components to your NetworkManager object
   1. The Mirror Network Manager
   2. The Mirror Telepathy Transport (Script)
   3. The Mirror Network Manager HUD
4. Set the Network Manager -> Network Info -> Transport to the NetworkManager (Telepathy Transport) component

5. Create a new 3D Object in your scene, selecting a Cube and name it Player
6. Add a component to your Player object
   1. The Mirror Network Identity
7. Create a new folder in your Assets/ directory, called Prefabs
8. Drag the Player object from your scene into the Assets/Prefabs/ folder, creating a Player prefab
9. Select your NetworkManager in your scene. Drag your Assets/Prefabs/Player prefab into the Network Manager -> Player Object -> Player Prefab

9. Delete the Player object from the Scene. The prefab will be loaded into the scene dynamically when players join during gameplay

Configuring Basic Player Controls

1. Create an new folder in your Assets/ directory called Scripts if one does not yet exist
2. Create a new MonoBehaviour Script in Assets/Scripts/, calling it Player
3. Open the Assets/Scripts/Player.cs file in your editor of choice
4. Replace the file's contents with the code below

using Mirror;
using UnityEngine;

namespace PlayerPrefab
{
    public class Player : NetworkBehaviour
    {
        void HandleMovement()
        {
            if (isLocalPlayer)
            {
                float moveHorizontal = Input.GetAxis("Horizontal");
                float moveVertical = Input.GetAxis("Vertical");
                Vector3 movement = new Vector3(moveHorizontal * 0.1f, moveVertical * 0.1f, 0);
                transform.position = transform.position + movement;
            }
        }

        void Update()
        {
            HandleMovement();
        }
    }
}

10. Back in your Unity Editor, double click the Player prefab to open it
11. Add two components to your Player prefab
    1. The Player.cs script you just wrote
    2. The Mirror Network Transport (Reliable)

Testing It Out

1. Re-open your Scene
2. Press play on both your main Unity Editor and the clone that ParrelSync is mirroring to
3. In one editor, select "Host (Server x Client)"
4. In the other, select "Client", leaving the fields as is
5. When you move your cube in one editor with WASD, you should see it move in the other editor as well
6. Congratulations! You have an MVP of a multiplayer game in Unity